Apparatus and method for testing the performance of a vehicle

Abstract

An apparatus for testing the brakes, wheel alignment, suspension, transmission, and engine of motorized wheeled vehicles, includes a dynamometer for self-calibration. A platform supports a road vehicle to be tested. Two or four pairs of short high-inertia rollers are revolvably supported adjacent to the platform, and positioned to individually support either the front wheels or the back wheels of the vehicle. The rollers are drivable by a stationary vehicle resting thereon, each pair of high-inertia rollers supporting one vehicle wheel. A floating roller contacts the wheel to detect side forces. Sensors are connected to the rollers and a computer for data processing, display and recording is connected to the sensors. Speed of the rollers is monitored by an encoder having a resolution of at least 1000 pulses/sec. A preferred embodiment of the apparatus includes electric motors which can be connected to drive the rollers.

1. A vehicle testing apparatus, said apparatus comprising: a platform arranged to allow a vehicle to be placed thereon; at least two pairs of high-inertia rollers supported by said platform, each pair of said high-inertia rollers supporting one wheel of said vehicle and being drivable individually in the same direction; a flywheel connectable to said high-inertia rollers; sensor means connected separately to said each pair of said rollers and data processing means connected to said sensor means, said sensor means and said data processing means enabling testing of performance of said vehicle associated with each said one wheel of said vehicle; and a self calibration system adapted to facilitate calibration of said testing apparatus based on one or more signals received from said sensor means. 
     
     
       2. The testing apparatus as claimed in  claim 1 , wherein said at least two pairs of high-inertia rollers are at least 400 mm diameter. 
     
     
       3. The testing apparatus as claimed in  claim 1 , wherein said sensor means includes a load cell sensor. 
     
     
       4. The testing apparatus as claimed in  claim 1 , wherein said sensor means includes a wheel speed sensor. 
     
     
       5. The testing apparatus as claimed in  claim 1 , wherein said sensor means includes a force sensor associated with a brake pedal of said vehicle. 
     
     
       6. The testing apparatus as claimed in  claim 1 , comprising an engine speed sensor connectable to a vehicle engine to report engine speed. 
     
     
       7. The testing apparatus as claimed in  claim 1 , comprising an hydraulically-operated dynamometer, a plurality of weights, and a lever, and an hydraulic operating device, to enable calibration of said testing apparatus. 
     
     
       8. The testing apparatus as claimed in  claim 1 , comprising: a hydraulically-operated absorption dynamometer, said dynamometer connected to a high-inertia roller; a torque arm being connected to a braking mechanism at one end and an adjustable combination of weights at a second end; and an electronic load cell associated with said torque arm, to measure the force on said arm. 
     
     
       9. The testing apparatus as claimed in  claim 1 , wherein said flywheel is to measure inertia. 
     
     
       10. The testing apparatus as claimed in  claim 1 , wherein said flywheel is connected to said pair of high-inertia rollers using a clutch. 
     
     
       11. The testing apparatus as claimed in  claim 1 , wherein said high-inertia rollers are connectable to at least one electric motor allowing said rollers to drive the vehicle wheels resting thereon. 
     
     
       12. The testing apparatus as claimed in  claim 11 , wherein said electric motor is to enable self-calibration of said testing apparatus. 
     
     
       13. The testing apparatus as claimed in  claim 11 , further comprising a belt drive to connect said pair of high-inertia rollers to said electric motor. 
     
     
       14. The testing apparatus as claimed in  claim 1  further provided with a floating roller positioned between said inertia rollers and above the center thereof and being connected to means urging said floating roller upwards into contact with a vehicle wheel thereabove. 
     
     
       15. The testing apparatus as claimed in  claim 14 , wherein said floating roller is suspended to allow limited axial movement in response to side forces acting thereon when in contact with a revolving wheel of a vehicle, said floating roller further comprising a positioning sensor to measure said axial movement. 
     
     
       16. The testing apparatus as claimed in  claim 14 , wherein said sensor means includes an axial deflection sensor respondable to axial deflection of said floating roller. 
     
     
       17. A vehicle testing method, comprising: providing a vehicle testing apparatus, said apparatus including a self calibration system adapted to facilitate calibration of said testing apparatus based on one or more signals received from sensors, wherein the sensors are associated separately with each pair of high inertia rollers, each said pair of high-inertia rollers being drivable individually in the same direction and supporting one wheel of a vehicle; positioning said vehicle on a platform, at least two wheels of said vehicle resting on at least two pairs of high-inertia rollers respectively, each pair of said high-inertia rollers supporting one wheel of said vehicle; accelerating said vehicle; measuring performance of said vehicle associated with each said one wheel of said vehicle; and
 wherein said calibrating comprises: placing a weight on a torque arm associated with an hydraulically-operated absorption dynamometer; and calculating the thrust of a wheel, based on the length of a torque arm associated with said wheel, the weight of a torque arm associated with said wheel, and the brake drum radius of said wheel, running an electric motor to operate an high inertia roller at a selected speed; discontinuing said electric motor, and breaking said rollers; and calculating inertia enemy stored in the rollers. 
 
     
     
       18. The method of  claim 17 , wherein said calibrating comprises:
 placing a weight on a torque arm associated with an hydraulically-operated absorption dynamometer; and calculating the thrust of a wheel, based on the length of a torque arm associated with said wheel, the weight of a torque arm associated with said wheel, and the brake drum radius of said wheel, running a vehicle engine to operate an high inertia roller at a selected speed; shifting the gear of said vehicle to zero; apply the breaks of said vehicle; and calculating inertia energy stored in the rollers. 
 
     
     
       19. The method of  claim 17 , comprising positioning a sensor means associated with said one wheel of said vehicle, said sensor means to enable the measuring of said one wheel of said vehicle. 
     
     
       20. The method of  claim 19 , comprising providing a data processing means associated with said sensor means, said data processing means to enable testing of said one wheel of said vehicle.